"Steve Shapson" wrote in message
...
I have a 25'x25'x24" pond with a 60'x2' stream. 40% covered in plants.
4-6
6 inch goldfish, and some baby goldfish, a few frogs. External self
priming
pump and no skimmer or biological filter. No stones on the bottom of the
large pond. The water recirculates up to a 3'x3'x12" pool with stone in
it.
The water then cascades over a 36" fall into the stream. The pond is
relatively clear.

1. Do I need to install an expensive man made biological filter? If so,
can I use small stones in the smaller pond to act as surface area for
bacteria?

2. Do I need to clean the bottom of the main pond on a yearly basis? If
so,
why? Can I do damage to the natural system by stirring it all up?

3. Evaporation? Given the dimensions above and our summer temps in the
60's to 70's, I have noticed that the level of the large pond area has a
loss of about 1/8" for two days.
snip


Hi,
I'm a filter believer but you, perhaps, don't need one, yet. The reason?
You've got one already. Every surface in the pond/stream is already
colonized by bacteria. If you increase the number of fish beyond just enough
for mosquito control, then a filter may be needed and they will breed.
Filters are not necessarily expensive, there are many types out there.
Adding stones adds minimally to the surface area and maximally to cleaning.
If you did monthly 10% water changes you'll see benefits. Do the change like
this, first shut the pump down for a couple hours to allow settling. Then
pump/siphon/vacuum 10% of the water from the bottom of the large pond. Use
this water to fertilize something. Refill by splashing water on the surface,
do not put the hose in the pond, this aerates and out gasses some of the
nasties. If you keep it to 10% and splash the water you can get by without
using dechlor. Some will argue with this and to be safe use Amquel or other
product.
1/8 inch in two days -- fergettaboutit.
HTH -_- how
no NEWS is good